Due to the worldwide spread of chemical arms, there is an ever-expanding danger of exposure to chemical warfare agents. Water sources are vulnerable to contamination by chemical warfare agents (CWA) and other hazardous materials. The U.S. Army M272 Chemical Agent Water Testing Kit represents a conventional kit that analyzes water for the presence of nerve agents but is insufficient for detection under many circumstances. For example, in hot arid climates where water consumption significantly exceeds 5 liters per day, the binary pass-fail characteristic of the M272 test kit for nerve agents is inadequate for determining potability since the allowable concentration of agent decreases proportionately with the increase of daily water consumption demands such that the maximum allowable daily dose of agent remains constant. For example, the allowable concentration of nerve agent in potable water is 20 ppb (0.02 mg/L) for temperate climate consumption of 5 liters per day. In hot arid climates the maximum allowable concentration is reduced to 5 ppb (0.005 mg/L) as water consumption could reach 15 liters per day. Thus, a CWA test kit with high sensitivity is an urgent need not only for military personnel in the field, but also civilians and agricultural operations in close proximity to a contaminated water source.
Another common problem with existing field test kits is that testing is labor intensive. For example, the M272 kit has small glass tubes fitted to a beaker using rubber fittings. To run a test, three glass capillary tubes are required, as well as the addition of three foil packets of chemicals to the glass beaker at separate times. The M272 kit produces color changes indicative of a positive or negative response for a test agent. At times, these color changes can be ambiguous and occur in a small area on a rounded surface of a capillary tube side wall potentially leading to the incorrect reading of results. Test operations performed while wearing protective equipment are especially prone to error. Protective gloves are also vulnerable to being breached by the need to handle and break glass micro capillary tubes that produce glass shards, thereby risking exposing a wearer to the agent.
Thus, there is a need for a sensitive, reproducible and field ready fluid test kit that can be used to detect chemically hazardous agents such as chemical nerve agents, other CWAs, pesticides, herbicides, or other environmental hazardous materials.